Production and Oxidation Resistance of HfB 2 –30 vol % SiC Composite Powders Modified with Y 3 Al 5 O 12

摘要: The HfB2–30 vol % SiC composite powders modified with a small (2 and 5 %) amount of Y3Al5O12 were synthesized by the sol–gel method. Such modification in producing an ultra-high-temperature ceramic corresponding composition optimized process temperature increased oxidation resistance stabilizing formed hafnium dioxide cubic or tetragonal form. It was determined that introduced X-ray amorphous phase distributed as thin film on particles diboride silicon carbide led to agglomeration latter; no formation individual observed. Investigation thermal behavior obtained air flow range 20–1200°C showed introduction virtually completely neutralized effect initial surface HfB2 700–800°C, shifted beginning maximum event from 756 808°C, decreased intensity this event.